Ruler



July 31, 1951 w. BOWSER, JR

RULER Filed July 28, 1948 a a. m. M Mi W n m m d a d W v. ,B

Patented July 31, 1951 RULER Wenard Bowser, Jr., Cleveland, Ohio, assignor to Universal Drafting Machine Corporation, Cleveland, Ohio, a corporation of Ohio Application July 28, 1948, Serial No. 41,089

3 Claims.

The present invention relates to graduated measuring instruments and, more particularly, to graduated rulers, scales and the like used in making drawings and layouts.

In conventional types of graduated rulers, etc., the graduations extend to the vertical side edge of the instrument; forexample, the vertical side edge of the beveled edge of a ruler. This construction produces a rough corner which is engaged by the lead of a pencil held normal to the drawing surface and moved along the edge of the instrument to produce a line in the making of a drawing or layout. The lead is abraded or cut away by the rough corner of the ruler, the action being somewhat analogous to that of a file and the cuttings fall upon and soil the drawing surface. In the event a scribing instrument is used, the rough edge formed by the graduations produces a vibrating effect.

Another disadvantage of conventional rulers is the fact that the side edge of the ruler is vertical which, together with the fact that the lead or point of the pencil or scribing instrument is tapered, causes the pencil or scriber to engage the upper corner of the vertical side edge and the point to be spaced from the lower corner of the ruler when the pencil or scriber is held in a normal manner, thus makin it more difiicult to draw a line at the exact desired location.

According to the present invention, the upper portion or part of the side edge or edges of the ruler or other instrument and into which part the graduations open is recessed or olTset inwardly with respect to the lower part of the side edge, which lower part is engaged by the pencil or scriber, in such a manner that the pencil or scriber will not come in contact with the rough corner formed by the opening of the graduations into the side edge and the lead of the pencil will not be abraded and cut away. The lower part of the side edge which is adapted to be engaged by the pencil or scriber is preferably tapered inwardly in an upward direction an amount approximately corresponding to the taper of the point of the pencil or scriber, with the result that when a pencil or scriber is held normal to the drawing surface and moved along the edge of the instrument, the lead or point will be in engagement with the edge of the ruler at or adjacent to the part thereof nearest to the drawing surface and the point of the pencil or scriber and the line drawn thereby will be close to the ruling edge of the instrument.

Further objects and advantages of the invention will be apparent to thos skilled in the art 2 to which it relates from the following description of the preferred embodiment described with reference to the accompanying drawing forming a part of this specification in which similar reference characters designate corresponding parts, and in which Fig. 1 is a perspective View of a portion of a graduated ruler embodying the present invention; and

Fig. 2 is a fragmentary end view through one edge of the ruler shown in Fig. 1 with the point of a pencil in engagement therewith.

Referring to the drawing, the reference character A designates a drafting machine ruler of conventional construction except for the side or ruling edges hereinafter specifically described. The ruler A has a substantially flat bottom surface H and a flat top surface Ill parallel with the bottom ll. Opposite sides of the ruler are beveled as at l2 to produce a relatively narrow ruling or side edge B along either side. A chuck plate l3 connected to the upper surface I0 in a conventional manner provides convenient means for detachably connecting the same to a drafting machine. The ruler A may be formed of any suitable material. Preferably it is made of light weight metal, such as, an aluminum or a magnesium allow. The beveled or sloped edges l2 adjacent opposite sides of the ruler proper are provided with the usual spaced graduations I5 which are preferably formed by scribing marks or Suitable shallow grooves fromed in the material of the ruler in any conventional manner.

According to the present invention, approximately the upper half I 6 of each of the side edges B of the ruler and into which part the graduations l5 open is recessed or offset inwardly slightly with respect to the lower half or part ll so as not to be engaged by the lead of a drawing pencil when held in a position normal to the drawing surface and moved along an edge to draw a line. The lower part I! of each of the side edges B is preferably tapered slightly inwardly in a vertical direction, preferably approximately at an angle to the plane of the bottom of the ruler equal to the taper of the pencil point or about 730.

The preferred form of side edge B for a ruler of the character described having an overall width of approximately one and one-half inches, a thickness of approximately .116", a fiat upper surface of approximately .74" wide, and beveled or sloping surfaces forming an angle of approximately 10 with the plane of the bottom of the ruler is shown in Fig. 2. The otherwise flat bot- 3 tom surface H of the ruler, as shown, has a slight bevel adjacent to the side ed e B of approximately 730, the width of which beveled portion is approximately .16". This surface is connected to a lower part I! of the side edge B which slopes inwardly in an upward direction, as previously stated, at an angle of approximately 7 30' by a radius or surface 20, the radius of curvature of which is approximately .005. From a point approximately .03" above the bottom plane or surface H of the ruler, the side edge B is formed of three reversely curved portions 2!, 22 and 23 which combine to form the upper part It of the side edge B and which merge into one another and the top beveled or sloped surfaces 2.

The graduations in the upper or beveled surface |2 of the ruler terminate in the upper portion 16 of the side edge B at a point spaced inwardly of the lower portion ll of the edge an amount such that when a pencil is moved along the side edge B while being held normal to the drawing surface, it will engage the smooth portion ll of the side edge and not engage that part of the side edge into which the graduations open. The reference character 25 designates a pencil held vertical to the drawing surface in position to be moved along the side edge 13 of the ruler to draw a line. It will be seen that the lower part of the point engages the smooth part I! of the side edge B of the ruler and the drawing surface adjacent to the lower corner of the ruler. It will also be seen that the graduations are spaced from the lead of the pencil a sufiicient amount to prevent any contact therebetween during normal movement of the pencil. With the construction shown, it will be apparent that the pencil may be moved along the ruling edge to draw a line without the lead of the pencil being abraded away by the rough corner produced by the graduations and that the lower end of the lead will be adjacent to the lower part of the ruling edge, with the result that the line can be accurately located and the drawing surface will remain clean.

While the preferred embodiment of the invention has been shown and described in considerable detail, the invention is not limited to the particular construction shown and it is my intention to cover hereby all modifications thereof which come within the practice of those skilled in the art to which the invention relates and within the scope of the appended claims.

Having thus described my invention, I claim:

1. In a graduated measuring instrument of the character referred to, a member having a bottom surface and a top surface connected by a side edge, said side edge comprising a planar portion extending from adjacent to said bottom surface upwardly to provide a flat surface to engage an appreciable length of a side of a pencil point drawn along said side edge, said portion terminating short of said top surface and an upper portion offset slightly inwardly of the first mentioned portion and interconnecting said top surface and the first mentioned portion, and graduations in said top surface opening into the off-set portion of said side edge, whereby a pencil drawn along said side edge does not engage the outer ends of said graduations.

2. In a graduated measuring instrument of the character referred to, a member having a bottom surface and a top beveled surface connected by a side edge, said bottom surface being relieved slightly adjacent to said side edge to raise the corner therebetween slightly above the plane of said bottom surface, said side edge comprising a smooth planar portion extending upwardly from said corner and terminating short of said top surface and an upper portion offset inwardly of the first mentioned portion and interconnecting the top surface and the first mentioned portion, said portions being connected by a curved surface, and graduations in said top surface opening into said upper part of said side edge, whereby a marking instrument drawn along said side edge slides along said smooth planar lower part and is prevented from engaging the outer ends of said graduations.

3. A graduated measuring instrument of the character described comprising, a member having a bottom surface and a top surface connected by a side edge, the said side edge including a smooth planar part extending from adjacent to said bottom surface upwardly and terminating short of said top surface to provide a flat surface to engage an appreciable length of a side of a, pencil point drawn along said side edge, said part inclined inwardly at an angle in the order of 730 with respect to a plane vertical to said bottom surface and an upper part offset inwardly relative to the first mentioned part, and graduations in said top surface with the outer ends of said graduations opening into said upper part of said side edge thereby terminating short of said planar part, whereby a marking instrument drawn along said side edge slides along said smooth planar part and is prevented from engaging the outer ends of said graduations.

WENARD BOWSER, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,029,225 Rigaumont June 11, 1912 2,182,027 Little Dec. 5, 1939 2,415,926 Wilt Feb. 18, 1947 FOREIGN PATENTS Number Country Date 14,410 Great Britain 1903 24,788 Great Britain 1901 185,692 Switzerland Aug. 15, 1936 292,795 Great Britain June 28, 1928 

